Water-resistant carboxylic acid-polyhydric alcohol resin



Patented Apr. '24, 192

UNITED STATES PATENT OFFICE.

CHARLES R. DOWNS, OF GLIFFSIDE AND LOUIS WEISBERG, OF GRANTWOOD, NEW

JERSEY, ASSIGNORS TO THE BARRETT COMPANY, A CORPORATION OF NEW JER- SEY.

WATER-RESISTANT CARIBOXYLIC ACID-POLYHYDRIC ALCOHOL RESIN.

No Drawing. Original application filed December 22, 1920, Seria1 No.432,408. Divided and this application filed September 7, 1921. SerialNo. 498,997.

aliphatic acid alone and also with a mixture of varying proportions ofboth an aromatic dibasic and an aliphatic dibasic acid. See U. S.Patents: 1,082,106, Dec. 22, 1913;

1,091,627, Mar. 31, 1914; 1,091,628, Mar. 31, 1914; 1,091,732, Mar. 31,1914; 1,098,728, June 2, 1914; 1,098,776, June 2, 1914; 1,098,- 777,June 2,1914; 1,108,329, Aug. 25, 1914;

. 1,108,330, Aug. 25, 1914; 1,108,331, Aug. 25,

1914; 1,108,332, Dec. 1, 1914.

'In the .case of those materials from glycerol and phthalic acid (ananhydrideforming aromatic dib'asic acid)' alone this combination hasbeen observed to pass through three stages, a lirst solid stage (theA-stage), a second solid stage (the B-stage) and a third solid stage(the C-stagc). The ultimate industrial utility of these resiuou productsliesin their use in molding, and like compositions. For this theabove-dcscribed C-stage product is very superior to Aug. 25,1914;1,119,592,

the corresponding' B-stagi f product and can be used successfully in alarge number of cases where the B-stage product is l'isclcss.

In the case of those materials from glycerol and a dibasic aliphaticacid or a mixture of dibasic aliphatic. acid and an anhydride-forniing(libasic aromatic acid, a solid product other than that correspondingto. the B-stage product of the glycerol-aromatic dibasic acid 'roup hasnever been described or indicatec, although such B-stage products havethemselves been knownv for many years.

Now, it remained for us to discover that these relatively uselessB-stage products can be converted into very useful and highly desirableproducts which are then among the very best insulating materialsavailable to the industries.

In addition we have also. discovered that useful C-stage' products canbe made from the less useful B-st-age products resulting from glyceroland a polynuclear aromatic acid, such as diphenic acid, 1.8 naphthalicacid, benzoyl-bcnzoic acid, methyl-benzoylbcnzoicacid andchlor-bcnzoyl-benzoic acid, and an aliphatic dibasic acid. Furthermore,we have also discovered that a tribasic aliphatic acid, such as citricacid and male malic acid, can be cmployed in place of dibasic aliphaticacids, in producing useful C- sl'age products either alone or in mixturewith the above-namedaromatic acids.

In converting these relatively useless 13-- stage products into our newproducts,'we have thereby caused the latter to retain substantially allof the elasticity and flexibility 'lhese changes, alone or together,would not addlo the utility of the B-stage products in any substantialmanner. However, our new products do differ from the B-stage productsfrom which they are respectively derived in one most essentialparticular and the one which enables our new products to be used undercircumstances where the corresponding B-stage products cannot beemployed at all. These B-stage products are all decomposed or so alteredby Water that they cannot be employed in places where watcr'contact isunavoidable such as in submarine cables or in exterior and openly ex-'posed positions where they are subject to action of dew, rain, snow orfrost. The B- stage products under these conditions be.-

come soft or spongy or porous, lose in elasticity and flexibility andalso lose in cohesiveness, resistance to shock, friction and to thepassage of electric current, while our new products suffer no materialchange in any or all of these respects through such water contact, whileat the same time they can equally well be employed in any and all otheruses to which the B-stage'products have been successfully put.

To effect this change of the old B-stage productsabove referred to intoour new products, we apply prolonged and high heat ing to these B-st-ageproducts until thev becomes coated with a bloom, always in less than twominutes; these B-stage products, when further properly heated, remaininfusible but lose the above described sensitiveness to water when theC-stage has been reached. These properties are so sharp and socharacteristic that an operator can, withcertainty, determine when hehas arrived at each of these three stages, when making these materialsin bulk. v

l/Ve have employed the following polybasic aliphatic acids; among. thedibasic acids we have employed and found useful are the following:fumaric acid; 'maleic acid; malic acid; succinic acid and tartaric acid;among the tribasic acids we have employed and found useful are citricacid and malo malic acid.

We have employed the following mixtures of the foregoing as well asothers not mentioned below. The figures in the table represent themolecular proportions of each acid used.

Succinic Fuxnaric I acid Tartalric acid acid acid,

Accordingly, theexpression phthalic acid a", used above and hereinafter,when not otherwise specified or indicated, is intendedto designate boththe acid as such or its equivalent anyhdride.

benzoic acid and chlor-benzoyl-benzoic acid,

ample, in the following table:

No Phthalic Fumaric Maleic Malic lSuccinic' Tartaric acid acid acid acidacid acid VVo have employed glycerol, glycol, diglyccrol andtriglycerol, all of which are polyhydric' alcohols or polyhydricalcoholic bodies. WVe make no claim to a resin made from phthalicanhydride alone because this is the subject of U. S. Patent 1,108,330,of August 25, 1914. We have discovered, however, that diphenic acid, 1.8naphthalic acid and the benzoyl-benzoic acids form with the abovementioned alcohols resins which are unaffected by water and we hereinclaim these resins as part of our invention. Of the variousbenzoyl-benzoic acids we have" used benzoyl-benzoic acid,methyl-benzoylwhich we made by condensation of phtlialic anhydride withbenzol, toluol and clilor-benzoyl respectively in the presence ofaluminum chloride, in the manner well known to chemists, and haveobtained satisfactory resins.

We have also made resins with each of these. aromatic acids mixed withone or more of the previously mentioned polybasic aliphatic acids andhave obtained satisfactory and useful results.

PRODUCING THEsE PRODUCTS IN BULK.

Example I.Part A.

A-stage resin from glycerol and malez'o acid-Heat together quantities ofglycerol and maleic acid in the proportion of one molecular weight ofglycerol to one molecular weight of acid. The acid dissolves, forming ahomogeneous mass. As the heating is ll continued, the melting pointgradually rises, and the material, which at first is quite sticky andviscous, eventually loses its stickiness and becomes more solid whencold. The completion of the first reaction can'be ascertained by takingout a small sample, and allowing it to cool. If the cooled product isviscous or tenaceous but not sticky, the reaction hasgone far enough. Atthis stage the product is soluble in acetone, making a clear solutionuseful as a-varnish. By this time the melting point is usuall. over 90C. and may be as high as (melting points taken by the method describedon page 821, vol'. 10, Journal of Industrial and Engineeri in 'ingChemistry). The time required to reach this point may vary according tothe temperature at which the heating is conducted, the bulk of thematerial employed, and the rate of stirring. 'It is seldom advantageousto let this temperature exceed 200 C. as it is then diflicult to controlthe next step in the reaction. On the other hand, it is desirable tokeep the temperature as high as possible (i. e., as near 200 C aspossible) because, the reaction otherwise proceeds slowly. For example,abatch of two pounds may be converted at 170 C. in approximately hours.If the material is cooled before the next stage of the reaction sets in,the product obtained is fusible and soluble in cold acetone.

This resin is also soluble at room.temperature in ethyl alcohol andethyl acetate al-' though not so much as in acetone. It dissolvesslightly in benzene. Cold water acts on it rapidly, causing it to becomediscolored and soft.

Example l'Pa-rl B.

B-sta e resin from glycerol and malez'c acz'cl.Heat the product ofExample 1- Part A until aspecimen on suitable test shows that it is nolonger fusible, that itis insoluble in cold acetone, and also that it isaffected when submerged in boiling distilled water for. two minutes. Thetemperature of heating may be as high as in Part A, but in 'lhat casethe reaction becomes violent, frothing and evolution of heat take place,and the material becomes filled with bubbles. This frothy product mayberendered ho.-

mogeneous by comminuting it and then molding it under heat and-pressure.A bub ble-free product may be obtained directly, however, by heating ata temperature properly at or near the melting point of the A- stageresin; the maximum temperature should not be above about 135 C. and thetemperature may be as low as 90 C. or lower. By whichever method it isobtained, the resin is infusible and has no true melting point, althoughit softens sufiiciently to be Example I Part 0.

O-s tage resin from glycerol and maleic acid-Heat the product fromExample I Part B to a temperature of 17 O-200 0. until a test specimenwhen submerged for'two minutes in boiling distilled water does not showa bloom. on its surface. The time-re- 'quired to accomplish this cangedepends on the temperature used and on the bulk of the material heated.\Vith a large bulk of time is required to equalize the temperature.

The final temperature may be as high as 250 C. when time is important.For exam ple, a batch of two pounds may be converted at 170 C inapproximately 30 hours.

In place of maleic acid of Example I, we have used the follow'ingmalicacid; fumaric acid; succinic acid, and malo-malic acid, and withsatisfactory results. More over, we haveused various mixtures of theseacids as well as mixtures containing one or at room temperature in thefollowing sol vents: acetone, ethyl alcohol, benzene, ethyl acetate,chloroform, turpentine, ether, linseed oil, China wood oil,-andpetroleum transformer oil. They are infu'sible but soften suflicientlyat temperatures above 140 C. to be molded under pressure. Mechanically,electrically, and chemically, these new prod ucts are'superior to the Aand B-stage products from which they are derived. Thus they are hard,tough, elastic, and well suited to the ordinary machining operations.They are resistant to heat, although they burn when put in a flame'. Theinsulating value of the C-stage resins is considerably higher than thatof the respective B-stage resins from which they are derived. The newproducts, moreover, are resistant to cold and to boiling Water.Prolonged contact with cold water does not diminish the lustre or polishof the surface, and thewater remains neutral to litmus. They aresubstantially unattached at room temperature by 20% solutions ofsulphuric, hydrochloric, nitric, or acetic acid, but they will notwithstand concentrated sulphuric acid or hot. concentrated nitric acid.They are not materially attacked within one hourby a 20% solution ofcaustic soda at the ordinary room temperature. However,

-on boiling in contact with this solution, the resins are decomposed,forming alcohols and sodium salts corresponding or related to thealcohols and acids used in their manufacture.

While these new C-resins. canv be used as such for certain purposes, thebest, most convenient and practlcal method of manufacture ill.)

is to apply the final heat treatment at the place or in the form oftheir ultimate use.

This is particularly the case when fillers are to be incorporated withthe resin, as itis often more convenient to compound the resin andfillers before the final heat treatment is applied.

For example, thdfinished C-resin may be finely ground, mixed with asuitablefiller if desired, and molded by the application of heat andpressure in the way usual in such operations. We have found that We canour ploy not only the more expensive kinds of Emample H.

Producing a molded article containing 0- rcsin from the B-rcsim-TheB-resin and the filler, or fillers, aregroundseparately and thenthoroughly mixed in the Way usual in such operations. All the materialsmust be finely ground to produce an even mixture. The relativeproportions of resin and filler will naturally vary according to theparticular purpose forwhich the molding composition is intended. Themixture thus produced may be molded under heat and pressure, and thefinal heat treatment, as in Example IPart C, then applied with themolded object still in the mold, or the heat treatment may be appliedfirst and the composition then molded. It is not always necessary tocarry out the entire heat treatment in the mold, and the molded objectmay be removed as soon as it has attained suflicient rigidity tomaintain its proper form under further heating, thus releasing, the moldfor further use and consequently cheapening the process.

Example [I].

Producing a molded article containing 0- resin from the B-rcsin.TheB-resin is finely ground and allowed tostand in contact with acetone fora considerable time. The powdered resin swells and forms a jelly-likemass, which is also a suitable form for compounding with a largeproportion of filler by kneading or passing between rolls in the usualway in such operations. The composition thus produced is heated to driveoff any excess of solvent and may then be handled as in the precedingexample. Alternatively, the composition may be molded before driving offthe solvent, and the solvent may then be driven off while the object isstill in the mold.

Example I V stage, the'composition is then ground and,

molded under heat and pressure in the usual way. Alternatively, thecomposition is heated only to the B-stage and is then molded and treatedas under Example II.

In making a C-stage resin which is to be molded or a molding compositioncontaining a C-stage resin, it is not necessary to complete the heattreatment entirely before the molding operation is carried out, but theheat treatment may be interrupted at such a stage that the heat appliedin the subsequent molding operation suffices to produce a finishedC-stage product.

Our new products can be distinguished with certainty from all otherheretofore known products by making the following two tests:

I. Place a specimen thereof in boiling dis .v

tilled water; if its surface remains bright and does not become dull intwo minutes, it is water-resistant in the sense we have herein used andwill hereafter use that expression.

II. Boil a specimen, say 1 gram, with ten times its hull; of a 20%solutionof caustic soda in water until all or nearly all has gone intosolution; filter; cool; acidify with hydrochloric acid. From the productof these operations tartaric acid, fumaric acid or succinic acid can allbe recovered as such by means usual with chemists for such purposes.from such resins in whose production they have been employed. Maleicacid and malic acid may be recovered partly as such, but these acids,when used for making our new products, may also be recovered entirely orin part only as fumaric acid, which is a well known transformationproduct of each of those two acids. We have described generally acontinuous and continuing procedure from a mixture of glycerol and anacid or acids to the final water-resistant (I-stage resin, but we wishit to be understood that either such a continuous or such discontinuousprocess can be used with equal satisfaction. I That is, we may proceedfrom the glycerol and acids to either the A-slagc or the .B-stage andsubsequently to the G-stage, or we may begin with the A-stage or B-stageresin and proceed to C-stage resin therefrom.

These resins all belong to the general class of plastics, and while wehave specifically mentioned that they can be used to produce a moldedarticle, it mustbe obvious to all that they are by no means restrictedto such eiumerated uses but can be used in many other places and in manyother operations and for many other purposes whereplastic materials canbe used. It is also obvious that our invention includes these resinswhether produced and used as such or whether produced in admixture orassociation with other ingredients, or used in admixture or association'with other ingredients, and that the term resin as used in the claims isnot to be construed as excludingthe association or admixture of otheringredients with said resins;

We claim 1. A water-resistant succimc ac dfglycerol resin.

2. The process of making a resin, which comprises heating'succinic acidand a poly-- hydric alcohol for about 20 hours between 180 and 200. 0.,then'below 135 C. for

- about hours, then between 170 and a 250 C. until a water-resistantresin results.

3.. The process of making a resin, which comprises heating succinic acidand glycerol for about 20 \hours between approximately 170 and 200C.,'then below 135 C. for about 10 ho rs, then between 170 and 250 0.,until water-resistant resin results. "i 4. Theprocess of snaking aresin, which comprises heating succinic acid, an:' anhy-- dride formingaromatic dibasic carboxylic acid and glycerol forabout 20 hours betweenapproximately170 and 200C then 'below 135 C. for about 10 h0 urs, thenbetween \170 and 250 C. until a water-resistant resin results.

5. The process of making a resin, which comprises heating 'succinicacid, an anhydrlde forming aromatic dabasic carboxylic acid anda'polyhydric alcohol for about 20 hours between approximately 17 0 and200 0., then below 135 C. for about 10 hours,'

comprises heatin then between 170 and 250. C. until a waterresistant'resin results.

'6. The process of making a resin,:which succinic acid, phtlialic acidand glycero for about; 20 hours between approximately 170 and 200 CJthenbelow for about 10 hours, then between 17 0 and 250 C. untila'water-resistant resin results.

"7,. A water-resistant succinic acid-anhydride forming varomatic dibasiccarboxylic' acid-glycerol resin. I

8. A water-resistant succinic acid-anhy- -hours1betWeen approximatelyand 200 C.,,then below 135 for about 10hours, then aromatic dibasiccarboxyliobetween 170 and 250 C. untila 'water-resistant resin results.I

12. A water-resistant'succinic'acid phthalic acid polyhydric alcoholresin. y

' In testimony where f We afiix our signat111'8S.' v

CHARLES R. DQWN S. LOUIS WEISBERG'

